The median survival of patients with unresectable gastric cancer treated with systemic chemotherapy is about 12 months. In patients with histologically proven unresectable or recurrent gastric cancer limited to the peritoneum and/or cancer cells in peritoneal cytology, the combination of i.p. paclitaxel with systemic chemotherapy reported a median survival time of 23.6 months. The peritoneal cytology turned negative for 86% of patients. In an updated report, gastrectomy was performed on 52 patients after disappearance or obvious shrinkage of peritoneal metastasis. In this cohort, the median survival time (MST) was 34.9 months. A phase III trial (PHOENIX-GC trial (Phase III study of S-1 plus intravenous and intraperitoneal paclitaxel versus S-1 plus cisplatin for gastric cancer with peritoneal metastasis )) comparing intraperitoneal(IP) regimen with systemic chemotherapy versus systemic therapy alone is currently opened for recruitment in Japan.